The present invention relates to a disk playback device for playing back information recorded on a disk such as a CD-ROM and, more particularly, to control over a rotation speed of a disk.
In recent years, the playback speed of the disk playback device such as a CD-ROM device has kept on increasing and, with this speeding-up, the disk rotation speed has also kept on increasing.
However, the increases in the disk rotation speed adversely cause vibrations or noises in the drive. More particularly, in media-exchangeable CD-ROM devices, DVD-ROM devices or the like, there are variations in mass eccentricities of media and the like, and accordingly excessive vibrations or noises sometimes occur depending on used media.
Thus, in recent years, it is common that when vibrations over a prescribed level occur, the maximum rotation speed of a disk is automatically reduced by a method in which a vibration sensor is mounted on a drive or vibrations are detected from a servo error signal or the like, thereby reducing the vibrations.
However, the vibrations and noises depend on users"" senses, and the extents to which the users feel unpleasant differ according to the use environments, users"" individual differences or the like. Further, there are certain variations in a vibration sensor mounted on a drive or a detection signal from a servo error signal for detecting vibrations, and the disk rotation speed is sometimes reduced though the user actually feels that the level is trivial.
Accordingly, as a device which arbitrarily reduces the disk rotation speed in accordance with an operation of a user who feels unpleasant, a disk playback device which can reduce the disk rotation speed by performing a prescribed operation to a disk ejection switch which is attached to the device is commercially available.
Hereinafter, this conventional disk playback device 61 which reduces the disk rotation speed using a disk ejection switch will be described with reference to FIG. 6.
FIG. 6 is a diagram for explaining the conventional disk playback device.
In FIG. 6, reference numeral 61 denotes a disk playback device according to this prior art. Numeral 12 denotes a host computer which issues a data playback request or the like to the disk playback device 61 as well as receives data which has been played back by the disk playback device 61.
Next, the structure of the disk playback device 61 will be described.
Numeral 101 denotes a disk on which various kinds of information data is recorded and which is exchangeably disposed. Numeral 102 denotes a disk motor for rotating the disk 101. Numeral 103 denotes a disk motor driving means for driving the disk motor 102 at a predetermined rotation speed. Numeral 104 denotes a playback means for playing back the various kinds of information data which is recorded on the disk 101. Numeral 105 denotes a volume control for adjusting an output level of an audio signal by a user operation. Numeral 106 denotes an audio output means for outputting audio data which has been played back by the playback means 104 as an audio signal. Numeral 107 denotes an interface means, which is connected with the host computer 12, for receiving the data playback request or the like from the host computer 12 as well as outputting data such as a program which has been played back by the playback means 104. Numeral 1003 denotes a disk ejection means for stopping the rotation of the disk 101 and ejecting the disk 101 from the disk playback device 61. Numeral 1004 denotes a disk ejection switch for outputting a switch operation which has been performed by a user. Numeral 110 denotes a control means for controlling respective components of the disk playback device 61. The control means 110 includes a switch operation analysis means 1001 for analyzing the switch operation of the disk ejection switch 1004, which has been performed by the user, and outputting a disk ejection command or a disk rotation speed control command; and a rotation speed control means 1002 for controlling the rotation speed of the disk 101 on the basis of a signal outputted from the switch operation analysis means 1001.
Next, control over the rotation speed of the disk 101 using the conventional disk playback device 61 will be described.
When a user operates the disk ejection switch 1004, the switch operation analysis means 1001 included in the control means 110 analyzes the operation of the disk ejection switch 1004 by the user. When the normal operation (for example, operation such as pushing the disk ejection switch 1004 once) is performed, the switch operation analysis means 1001 outputs a disk ejection command to the disk ejection means 1003, to stop the rotation of the disk 101 and eject the disk 101 outside of the device. On the other hand, when a specific operation (for example, operation such as continuing to press the disk ejection switch 1004 for a prescribed time or longer period) is performed, the switch operation analysis means 1001 outputs a command for reducing the rotation speed of the disk motor 102 to the rotation speed control means 1002, to reduce the rotation speed of the disk 101. To be more specific, when the user feels unpleasant due to vibrations or noises of the disk playback device 61, which result from the mass eccentricity of the disk 101 or the like, the user performs a specific operation using the disk ejection switch 1004 to output a command for reducing the rotation speed of the disk 101 to the rotation speed control means 1002. The rotation speed control means 1002 which has received the command for reducing the disk rotation speed controls the disk motor driving means 103 to reduce the rotation speed of the disk motor 102, thereby reducing noises or vibrations.
However, in the above-mentioned conventional disk playback device, a specific operation that is not the normal operation for disk ejection is performed to the disk ejection switch 1004 to reduce the rotation speed of the disk. Accordingly, there is a high risk of erroneous operations of the disk ejection switch 1004. Further, it is quite difficult to minutely set the degree of reducing the disk rotation speed, or restore the playback speed which has been once reduced to its previous speed. When this is to be realized, a complicated operation of the disk ejection switch 1004 by the user is further required, whereby the risk of erroneous operations of the switch is increased.
The present invention is made in view of the aforementioned problems and has for its object to provide a disk playback device which neither requires an additional component in the disk playback device nor affects a disk reading operation even when an erroneous operation is performed, and whose disk rotation speed can be arbitrarily changed by the user with a simple operation.
To attain the aforementioned object, a disk playback device according to an embodiment of the present invention comprises: a playback means for playing back data on a disk; an audio output means for outputting audio data as an audio signal to the outside when the audio data is played back by the playback means; an audio level manipulation means for manipulating an output level of the audio signal which is outputted by the audio output means; a detection means for detecting a set value of the audio level manipulation means; and a rotation speed control means for controlling a rotation speed of the disk which is played back by the playback means, and the rotation speed control means controls the rotation speed of the disk on the basis of the set value detected by the detection means.
According to the disk playback device of the present invention, the rotation speed is controlled on the basis of the set value in the audio level manipulation means, whereby the users can freely change the disk rotation speed with a simple operation. Further, the rotation speed of the disk is controlled using the audio level manipulation means, whereby the structure of the disk playback device can be produced easily and inexpensively without adding a new component for controlling the rotation speed of the disk.
According to a disk playback device of the disk playback device discussed above, the rotation speed control means controls the rotation speed of the disk on the basis of the set value detected by the detection means only when the audio signal is not outputted from the audio output means.
According to the disk playback device of the present invention, the playback speed of the disk is not changed while the audio signal is outputted. Thereby, the audio level can be changed using the volume control while the audio signal is outputted, and there can be provided a disk playback device which exerts less influence upon the playback operation of the disk even when an erroneous operation is performed while the audio signal is outputted.
According to a disk playback device of another embodiment of the present invention, further to the disk playback device discussed above, the audio level manipulation means is a variable-resistance volume control for changing the output level of the audio signal which is outputted from the audio output means.
According to the disk playback device of the present invention, the rotation speed of the disk is controlled using the variable-resistance volume control, whereby less influence is exerted upon the disk playback operation of the disk playback device even when an erroneous operation is performed, and the user can freely change the disk rotation speed with a simple operation. Further, by controlling the disk rotation speed using the variable-resistance volume control, the structure of the disk playback device can be produced easily and inexpensively without adding a new component for controlling the disk rotation speed.
According to a disk playback device of another embodiment of the present invention, further to the disk playback device discussed above, the audio level manipulation means is an electric volume control comprising a switch means; and an audio level set value storage means which can vary a set value by an operation of the switch means, and changes the output level of the audio signal outputted from the audio output means on the basis of the value in the audio level storage means.
According to the disk playback device of the present invention, the rotation speed of the disk is controlled using the electric volume control. Thereby, less influence is exerted upon the disk playback operation of the disk playback device even when an erroneous operation is performed, and the user can freely change the disk rotation speed with a simple operation. Further, by controlling the disk rotation speed using the electronic volume control, the structure of the disk playback device can be produced easily and inexpensively without adding a new component for controlling the disk rotation speed.
According to a disk playback device of another embodiment of the present invention, further to the disk playback device discussed above further comprises a disk moving means for placing a disk in a playable state; and rotation speed control means for performing control for playing back data on the disk at a preset rotation speed of the disk immediately after the power is turned on or immediately after the disk is placed in a playable state by the disk moving means.
According to the disk playback device of the present invention, data on a disk is played back at a rotation speed of the disk, which is arbitrarily preset when the power is turned on or when the data is played back immediately after the disk is placed in a playable state. Thereby, the disk rotation speed which has been changed by the user operation is reset after the power is turned off or the disk is ejected, and the playback can be always performed at a fixed disk rotation speed after the power is turned on or the disk is placed in a playable state.
According to a disk playback device of another embodiment of the present invention, further to the disk playback device discussed above, the preset rotation speed of the disk is a maximum rotation speed of the disk playback device.
According to the disk playback device of the present invention, data on a disk is played back at the maximum rotation speed of the disk playback device when the power is turned on or when the data is played back immediately after the disk is placed in a playable state. Thereby, the disk rotation speed which has been changed by the user operation is reset after the power is turned off or the disk is ejected, and the playback can be always performed at the maximum rotation speed of the disk playback device after the power is turned on or the disk is placed in a playable state.
According to a disk playback device of another embodiment of the present invention, further to the disk playback device discussed above, when the disk rotation speed with respect to the set value detected by the detection means is over the maximum rotation speed of the disk playback device, the rotation speed control means makes the set value the maximum rotation speed of the disk playback device.
According to the disk playback device of the present invention, even when a disk rotation speed with respect to a set value of the volume control, which has been changed by the operation of the volume control by the user is over the maximum rotation speed of the disk playback device, the disk rotation speed with respect to the changed set value is made the maximum rotation speed of the disk playback device. Thereby, even when the set value of the volume control is changed to any value, the disk rotation speed can be controlled on the basis of the disk rotation speed with respect to the set value of the volume control, whereby the user can freely change the disk rotation speed by the operation of the volume control.
A disk playback method according to an embodiment of the present invention comprises: a playback step of playing back data on a disk; an audio output step of outputting audio data as an audio signal to the outside when the audio data is played back in the playback step; an audio level manipulation step of manipulating an output level of the audio signal which is outputted in the audio output step; a detection step of detecting a set value in the audio level manipulation step; and a rotation speed control step of controlling a rotation speed of the disk on the basis of the set value detected in the detection step only when the audio signal is not outputted in the audio output step.
According to the disk playback method of the present invention, the rotation speed is controlled on the basis of the set value in the audio level manipulation step, whereby less influence is exerted upon the disk playback operation of the disk playback device even when an erroneous operation is performed, and the user can freely change the disk rotation speed with a simple operation. Further, by controlling the disk rotation speed using the set value in the audio level manipulation step, the structure of the disk playback device can be produced easily and inexpensively without adding a new component for controlling the disk rotation speed.